Tiny Cracks in the Gelcoat

[rescuesailor]

I have tiny cracks in the gelcoat of the hull on my boat. I have checked to make sure they are not the result of structural failure. They do not seem to be. However they cover some large areas of the hull and deck. I want to make sure they do not show through the new paint job. i have been sanding and grinding out knicks and holes bu t there are too many of the cracks! Any suggestions?

[Hirilondë]

The only way to absolutely guarantee they never show through is to remove the gelcoat of your boat completely or open each and every one up and fill them. But that is not practical at all. The next best thing is to use a high build primer either as separate coats alternately with the regular primer, or mixed into the regular primer to fill and/or bridge the cracks. Consult the manufacturer of your paint for details. The down side to this is that a couple years down the road some of them may show through the paint to varying degrees.

[Rachel]

I don't have anything to add to what Dave said, as I agree with him. But I just thought I would post so that when you are mentally tallying up opinions .... well, I always like to see a wide range, so even if someone is just basically agreeing I prefer that they post too.

I'm somewhat of a perfectionist, so it would drive me nuts to do a really thorough, expensive, two-part paint job and then just watch and wait for the cracks to come back. OTOH, removing the gelcoat is a big job (but one you only have to do once, and I have had boats with 20-year-old Awlgrip jobs that still looked great (Great Lakes climate).

I suppose it's possible that if you have some areas that are really much worse than others, you could remove the gelcoat in those areas only, and do the "rout and fill" method in the lesser-cracked areas. I have seen variations where some cracks are really extremely tight thin "lines," whereas others are much more friable "looser" cracks.

Any pics?

Rachel

[Shoalcove]

Grinding off all the gelcoat is a lot of work. The decision will depend on the old risk/reward equation and your expectations for the paint job. I painted my CL35 2 years ago. I used Perfection 2 part and rolled and tipped outside. I knew that the finish would not be absolutely perfect. It's really nice but not perfect. I also sail with my kids and I knew I'd soon have a dinghy ding or two. Therefore, I sanded and filled the best I could but didn't worry about the very fine hairline cracks that I had. The more obvious ones I widened out with a juice can opener and filled and faired. The primer coats covered the cracks and I haven't seen them since. My paint job cost 10% of a pro job and looked about 90% as good when finished. After a couple years the pro jobs have dings too so I get more satisfied every year! Your desires will dictate your course of action but I like to remind myself that "perfection is the enemy of progress"! Good luck